The invention is directed to the field of neutron detection and measurement and particularly to the field of detection of neutron energies. The invention has special application to technologies where a relatively low neutron flux rate is observed.
Neutron detectors which measure the presence of neutrons, namely neutron flux, as opposed to energy, are known in the art. Examples of such detectors are counters or ionization chambers filled with boron containing gases such as BF.sub.3 in which neutrons are detected by the production of ionizing alpha particles when the neutron reacts with boron-10. For fast neutrons, ionization chambers may also be fabricated by utilizing a hydrogenous gas and taking advantage of the elastic scattering of protons which are subsequently utilized to ionize the gas.
When neutron energy measurements are desired, as opposed to simple flux measurements, the art teaches utilization of time-of-flight methods in which the travel time of neutron pulses are measured where again the neutron is detected as the end point by means of an ionization counter.
Further, with the discovery of "cold fusion"from experiments of Steven E. Jones et al. at Brigham Young University, there is an ever increasing demand for neutron counters which can measure neutron energies at very low rates. Such counters are instrumental in confirming the existence of catalyzed fusion in which deuterons are infused into a host material with a resulting enhancement of nuclear fusion. In such systems, detection of the neutrons at the expected energies provides a measure of the reaction rate and thus energy produced. Such detectors may thus be termed calorimeters.